1. Field of the Invention
The invention relates generally to a liquid droplet ejecting apparatus that ejects liquid droplets.
2. Description of Related Art
A known liquid droplet ejecting apparatus, e.g., a serial ink jet printer, ejects liquid droplets. A known serial ink jet printer, e.g., the one described in Japanese Unexamined Patent Application Publication No. H09-226201 A, includes a transport mechanism that transports a recoding sheet of paper in a predetermined transport direction, a carriage that is reciprocally movable in a widthwise direction, e.g., a scanning direction, which is perpendicular to the transport direction of the recording sheet of paper, and an ink jet head mounted on the carriage. The known ink jet printer ejects ink droplets from a plurality of nozzles onto the recording sheet of paper while reciprocally moving the ink jet head with the carriage in the scanning direction. Thus, the known ink jet printer records a desired image or character on the recording sheet of paper transported by the transport mechanism.
In the known serial ink jet printer, as the speed at which the ink jet head ejects liquid droplets while moving in the scanning direction increases, the space between each dot formed on the recording sheet of paper in the scanning direction decreases, and, as such, the resolution of an image formed on the recording sheet of paper increases. Nevertheless, as the number of dots is increased to increase the image resolution, the size of data, e.g., dot data, for forming this increased number of dots becomes greater, it takes a longer time for data transmission to the printer and the like. In addition, it takes a longer time for the ink jet head to move in the scanning direction, e.g., make a pass, when an increased number of dots at fine dot intervals are formed on the recording paper. Thus, the print speed undesirably is decreased.
Further, in a known ink jet head, a plurality of individual ink flow passages that respectively communicate with a plurality of nozzles are branched off from one common ink chamber (manifold). Thus, ink is supplied from the one common chamber to the plurality of nozzles. When liquid droplets are ejected simultaneously from the plurality of nozzles that communicate with the one common ink chamber, pressure, e.g., ejecting energy, also is applied to ink in the plurality of individual ink flow passages corresponding to these plurality of nozzles simultaneously. After liquid droplets are ejected from all the nozzles, propagation of residual pressure waves, e.g., fluid crosstalk, through the common ink chamber occurs among the nozzles and among the individual ink flow passages that communicate with the nozzles. Mechanical vibrational energy that occurs at the time of ejection of liquid droplets also propagates between the adjacent individual ink flow passages, e.g., structural crosstalk. These crosstalk phenomena adversely affect the characteristics of ejection of liquid droplets from the nozzles.
Fluid crosstalk and structural crosstalk interfere with the ejecting energy applied to ink and causes the liquid droplet ejecting characteristics, e.g., the amount of liquid droplet and liquid droplet speed, to deviate. In addition, fluid crosstalk and structural crosstalk interferes with the accurate timing of ink ejection. Thus, fluid crosstalk and structural crosstalk in the known ink jet head causes print quality to decrease and are particularly problematic in high-resolution printing, such as printing a photograph or the like.